The resistance of a wire is R ; Omega. If it | vedclass

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(B) The resistance of a wire of length $l$,cross-sectional area $A$,and resistivity $\rho$ is given by $R = \rho \frac{l}{A}$.When the wire is stretch

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$n^2R$

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(B) The resistance of a wire of length $l$,cross-sectional area $A$,and resistivity $\rho$ is given by $R = \rho \frac{l}{A}$.When the wire is stretched to $n$ times its original length,the new length becomes $l' = nl$.Since the volume of the wire remains constant during the process,$V = A \cdot l = A' \cdot l'$.Substituting $l' = nl$,we get $A' = \frac{A \cdot l}{nl} = \frac{A}{n}$.The new resistance $R'$ is given by $R' = \rho \frac{l'}{A'}$.Substituting the values of $l'$ and $A'$,we get $R' = \rho \frac{nl}{A/n} = n^2 \left( \rho \frac{l}{A} \right) = n^2 R$.

The resistance of a wire is $R \; \Omega$. If it is melted and stretched to $n$ times its original length,its new resistance will be

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